1. Field of the Invention
The present invention relates to an apparatus and method for processing a slider, a load applying apparatus for processing a slider and an auxiliary device for processing a slider which are employed for chamfering edges of a slider used for a flying type magnetic head or the like.
2. Description of the Related Art
In general, a flying type magnetic head used in a magnetic disc drive or the like has a configuration in which a thin film magnetic head element is formed at the rear end of a slider. A slider generally has rail portions whose surfaces face a recording medium (air bearing surfaces) and has a taper or step portion in the vicinity of the end at the air inflow side such that the rail portions fly slightly above the surface of a recording medium such as a magnetic disc or the like because of a stream of air flowing in through the taper or step portion.
For example, as disclosed in Japanese unexamined patent publication (KOKAI) No. H6-282831, in order to prevent edges of a slider such as edges defined by the surfaces of the rail portions to face a recording medium and outer lateral walls of the rail portions from damaging the recording medium when the slider is inclined because of a shake or the like, a chamfering process is performed on the edges of the slider.
For example, as disclosed in Japanese unexamined patent publication (KOKAI) No. H6-12645, a method for chamfering on edges of a slider according to the related art is to put the surface of a slider to face a recording medium into contact with a diamond lapping sheet provided on an elastic element with a load applied thereto and to lap the slider by moving it relative to the diamond lapping sheet.
According to the above-described method for chamfering, a slider must be urged against the diamond lapping sheet by applying a load thereto. However, a problem has arisen in that the diamond lapping sheet can be cut by edges of a slider especially before the chamfering of the edges of the rail portions or at an early stage of the chamfering because the base material of the diamond lapping sheet is thin.
According to the above-described method for chamfering, it is further necessary during actual processing to urge a slider against the diamond lapping sheet by applying a load to a jig. On the contrary, the load must not be applied to the jig when the slider is attached to or removed from the processing apparatus. This necessitates a mechanism for applying the load to the jig only when needed.
A possible mechanism for this purpose is a mechanism having a weight with a shaft portion which can be put into contact with a jig at the lower end thereof and a large diameter portion greater in the diameter than the shaft portion and having a weight holding portion formed with a hole which allows the shaft portion of the weight to pass therethrough and which disallows the large-diameter portion to pass therethrough, for holding the weight movably in the axial direction of the shaft portion of the weight with the hole, the mechanism allowing the weight holding portion to be moved up and down.
However, such a mechanism has a problem in that the weight can not be smoothly moved relative to the weight holding portion because the shaft portion of the weight frequently rubs against the hole of the weight holding portion to generate chips (particles).
According to the above-described method for chamfering, the entire edges of a slider are substantially uniformly chamfered.
However, the above-described method for chamfering had a problem in that it does not allow a part of the edges of a slider, e.g., a region of the edges at the air inflow side of the slider, to be chamfered in a greater amount than in other regions of the edges even when it is desired.
A slider for a magnetic head is formed by cutting a wafer having a multiplicity of magnetic head elements formed in a matrix configuration in one direction to form blocks referred to as xe2x80x9cbarsxe2x80x9d which include a plurality of magnetic head elements arranged in a row, forming rail portions on the bars and thereafter cutting the bars into each separate slider. Referring now to a slider as disclosed in Japanese unexamined patent publication (KOKAI) No. H6-282831, outer lateral walls of two rail portions serve as lateral walls of a slider as they are. However, the configuration as disclosed in Japanese patent publication (KOKAI) No. H6-282831 has a problem in that rail portions can be broken off (chipping) as a result of mechanical processing to cut bars into sliders.
For this reason, sliders as shown in FIG. 47 have become popular in which rail portions 213 are formed such that lateral walls 214 of the rail portions 213 are located inside lateral walls 212 of a slider 211 or cut portions of a bar with a predetermined distance therebetween. A slider having such a configuration will be hereinafter referred to as xe2x80x9ca slider having a two-step structurexe2x80x9d.
In such a slider having a two-step structure, chamfering is also performed on edges of the rail portions. For example, as disclosed in Japanese unexamined patent publication No. H6-12645, a method for chamfering edges of rail portions according to the related art is to slide the slider on a diamond lapping sheet provided on an elastic element. FIG. 48 schematically illustrates the method for chamfering according to the related art. According to the method for chamfering of the related art, a plurality of sliders 211 are fixed to a jig 215 and are slid in two horizontal directions on a diamond lapping sheet 217 provided on a plate-like elastic member 216 formed from, for example, silicone rubber while urging them in the direction of the arrow indicated by a reference number 218 in the figure, thereby chamfering edges 219 of rail portions 213.
FIG. 49 is an enlarged view of the neighborhood of edges 219 of rail portions 213 (the region C in FIG. 48) which have been chamfered according to the method illustrated in FIG. 48.
As disclosed in Japanese unexamined patent publication (KOKAI) No. H2-301014, another method for chamfering according to the related art is to move a lapping tape back and forth under the guidance of a guide to thereby slide the lapping tape relative to rail portions of a slider.
There is a recent need for a reduction in the flying amount of a slider in order to improve the recording density. There is also a need for improved stability of the flying of a slider in order to increase access speed. Negative pressure sliders have recently come into use to satisfy such needs. In general, a negative pressure slider is formed with a projection for generating a negative pressure between the two rail portions thereof. In such a negative pressure slider, the surface toward a recording medium has a microscopic configuration and, especially, the height of the rail portions is significantly smaller than that in conventional sliders.
In such a negative pressure slider, as shown in FIG. 50, the small height of the rail portions has resulted in a problem in that a recording medium 225 can be put into contact with and damaged by an edge 224 defined by a lateral wall 222 of a slider 221 and a surface 223 of the slider toward the recording medium perpendicular thereto when the slider 221 is inclined. The above-described problem is significant especially in a hard disc device used in a portable apparatus such as a notebook type personal computer in which the slider is often inclined.
Under such circumstances, the inventors have proposed, for example in Japanese unexamined patent publication (KOKAI) No. H11-238214 and U.S. patent application Ser. No. 09/064,734, a technique for lapping and chamfering a plurality of edges having steps of a slider simultaneously by transforming a diamond lapping sheet using a wire. In this case, since processing accuracy is reduced if the tension of the wire is unstable, the tension of the wire must be made stable in order to improve processing accuracy.
It is a first object of the invention to provide an apparatus and method for processing a slider and a load applying apparatus for processing a slider which make it possible to prevent an edge of a slider from cutting a lapping member when the edge of the slider is lapped with the lapping member to chamfer the edge.
It is a second object of the invention to provide an apparatus for processing a slider and a load applying apparatus for processing a slider wherein a load can be applied to a slider holder for holding a slider only when needed during lapping on an edge of a slider to chamfer the edge and wherein the mechanism can operate smoothly.
It is a third object of the invention to provide an apparatus and method for processing a slider and auxiliary device for processing a slider which make it possible to chamfer a part of an edge of a slider in a greater amount than in other regions of the edge.
It is a fourth object of the invention to provide an apparatus and auxiliary device for processing a slider which make it possible to lap and chamfer a plurality of edges having steps of a slider simultaneously with improved processing accuracy.
A first slider processing apparatus according to the invention is an apparatus for lapping an edge of a slider having a surface to face a medium to chamfer the edge, comprising:
a slider holder for holding a slider;
a lapping member for lapping an edge of the slider held by the slider holder;
load applying means (apparatus) for applying a load to the slider holder so as to urge the slider held by the slider holder against the lapping member, capable of adjusting the load applied to the slider holder; and
moving means (device) for moving the slider held by the slider holder and the lapping member relative to each other such that the edge of the slider is lapped by the lapping member.
In the first processing apparatus according to the invention, the load applying means (apparatus) applies a load to the slider holder so as to urge the slider held by the slider holder against the lapping member, and the load applied to the slider holder is adjusted.
For example, the lapping member of the first processing apparatus according to the invention is in the form of a sheet.
For example, the load applying means (apparatus) of the first processing apparatus according to the invention has a plurality of weights for applying a load to the slider holder and load adjusting means (device) for adjusting the load by applying the load originating from the plurality of weights to the slider holder in a stepwise manner. In this case, for example, the weights include a shaft portion and a large diameter portion greater in the diameter than the shaft portion. The load adjusting means (device) includes weight holding portions in the form of a plurality of stages each formed with a hole which allows the shaft portion of the weight to pass therethrough and disallows the large diameter portion to pass therethrough for holding the weight movably in the axial direction of the shaft portion with the hole and includes weight holding portion moving means for moving the weight holding portion up and down. The load adjusting means (device) moves the weight holding portions downward with the weight holding portion moving means from a position in which the lower end of the shaft portion of the weight held by the weight holding portion at the bottom stage is located above the slider holder without contacting the slider holder to load the slider holder with the weights held by the weight holding portions in the form of a plurality of stages sequentially from the bottom stage. The weights comprise one or more blocks having a predetermined weight.
In the first processing apparatus according to the invention, a spiral (helical) groove may be formed on at least either the outer circumferential surface of the shaft portions of the weights or the inner circumferential surface of the holes of the weight holding portions.
For example, the lapping member of the first processing apparatus according to the invention may have a lapping surface, and the processing apparatus may further have a positioning device for positioning the slider holder such that a slider is put into contact with the lapping member in a state in which the surface of the slider to face a medium is inclined relative to the lapping surface of the lapping member. In this case, for example, the slider may include a plurality of edges having steps; the lapping member may have flexibility; and the processing apparatus may further have transforming means (device) for transforming the lapping member such that the plurality of edges having steps of the slider are simultaneously lapped by the lapping member.
In the first processing apparatus according to the invention, the slider may include a plurality of edges having steps, and the lapping member may have flexibility. The processing apparatus may further have a transforming device for transforming the lapping member such that the plurality of edges having steps of the slider are simultaneously lapped by the lapping member, which has a main body provided in a position opposite to the slider held by the slider holder with the lapping member sandwiched therebetween and a wire wound around the outer circumference of the main body for transforming the lapping member. The transforming device may further have an elastic member or a projection provided under a part of the wire located on the top surface of the transforming device.
A first method for processing a slider according to the invention comprises the steps of:
chamfering an edge of a slider having a surface to face a medium by lapping the edge with a lapping member for lapping an edge of a slider with the slider and lapping member moved relative to each other while applying a load to a slider holder so as to urge the slider against the lapping member; and
changing the load applied to the slider holder depending on the progress of chamfering.
In the first method for processing according to the invention, the lapping member is, for example, in the form of a sheet.
In the step of changing the load of the first method for processing according to the invention, the load applied to the slider holder may be increased in a stepwise manner depending on the progress of chamfering.
In the method for chamfering according to the invention, for example, the lapping member may have a lapping surface, and the step of chamfering may include the steps of putting the slider in contact with the lapping member with the surface of the slider to face a medium inclined relative to the lapping surface of the lapping member and lapping a predetermined edge of the slider with the lapping member while moving the slider and the lapping member relative to each other in a state in which the slider is in contact with the lapping member with the surface of the slider to face a medium inclined relative to the lapping surface of the lapping. In this case, for example, the slider may include a plurality of edges having steps; the lapping member may have flexibility; and the step of lapping may simultaneously lap the plurality of edges having steps of the slider with the lapping member by transforming the lapping member.
In the first method for processing according to the invention, for example, the lapping member may have a lapping surface; the step of chamfering may include a first lapping step for lapping a part of an edge of the slider in contact with the lapping member while moving the slider and the lapping member relative to each other in a state in which the slider is in contact with the lapping member with the surface of the slider to face a medium inclined relative to the lapping surface of the lapping member and a second lapping step for lapping a part of the edge of the slider in contact with the lapping member while moving the slider and the lapping member relative to each other in a state in which the slider is in contact with the lapping member with the surface of the slider to face a medium in parallel with the lapping surface of the lapping member.
In this case, for example, the slider may include a plurality of edges having steps; the lapping member may have flexibility; and the first lapping step may simultaneously lap the plurality of edges having steps of the slider with the lapping member by transforming the lapping member. The second lapping step may lap the plurality of edges having steps of the slider with the lapping member by transforming the lapping member. For example, the slider may include a plurality of edges having steps, and the first lapping step may include the steps of lapping the edges of the slider with the lapping member without transforming the lapping member and simultaneously lapping the plurality of edges having steps of the slider with the lapping member by transforming the lapping member having flexibility. The first lapping step may chamfer at least a part of an edge in contact with the lapping member into a slanting surface, and the second lapping step may chamfer the edge chamfered into a slanting surface at the first lapping step into a curved surface.
A first load applying apparatus for processing a slider according to the invention is an apparatus which is used for a slider processing apparatus for lapping an edge of a slider having a surface to face a medium to chamfer the edge, comprising a slider holder for holding a slider having a surface to face a medium, a lapping member for lapping an edge of the slider held by the slider holder and moving means (device) for moving the slider held by the slider holder and the lapping member relative to each other so as to lap the edge of the slider with the lapping member and which applies a load to the slider holder so as to urge the slider held by the slider holder against the lapping member.
The first load applying apparatus according to the invention comprises:
a plurality of weights for applying a load to a slider holder; and
load adjusting means (device) for adjusting the load by applying the load originating from the plurality of weights to the slider holder in a stepwise manner.
The weights include a shaft portion and a large diameter portion which is greater in the diameter than the shaft portion.
The load adjusting means (device) includes weight holding portions in the form of a plurality of stages each formed with a hole which allows the shaft portion of the weight to pass therethrough and disallows the large diameter portion to pass therethrough for holding the weight movably in the axial direction of the shaft portion with the hole and includes weight holding portion moving means (device) for moving the weight holding portion up and down.
The load adjusting means (device) moves the weight holding portion downward with the weight holding portion moving means from a position in which the lower end of the shaft portion of the weight held by the weight holding portion at the bottom stage is located above the slider holder without contacting the slider holder to load the slider holder with the weights held by the weight holding portions in the form of a plurality of stages sequentially from the bottom stage.
In the first load applying apparatus according to the invention, the load adjusting means (device) applies a load originating from the plurality of weights to the slider holder in a stepwise manner to adjust the load applied to the slider holder.
The weights of the first load applying apparatus according to the invention are constituted by, for example, one or more blocks having a predetermined weight.
In the first load applying apparatus according to the invention, a spiral (helical) groove may be formed on at least either the outer circumferential surface the shaft portions of the weights or the inner circumferential surface of the holes of the weight holding portions.
A second slider processing apparatus according to the invention is an apparatus for lapping an edge of a slider having a surface to face a medium to chamfer the edge, comprising:
a slider holder for holding a slider;
a lapping member for lapping an edge of the slider held by the slider holder;
load applying means (apparatus) for applying a load to the slider holder so as to urge the slider held by the slider holder against the lapping member; and
moving means (device) for moving the slider held by the slider holder and the lapping member relative to each other such that the edge of the slider is lapped by the lapping member.
The load applying means (apparatus) has:
a weight including a shaft portion which can be put into contact with the slider holder at the lower end thereof and a large diameter portion greater in the diameter than the shaft portion;
a weight holding portion formed with a hole which allows the shaft portion of the weight to pass therethrough and which disallows the large-diameter portion to pass therethrough for holding the weight movably in the axial direction of the shaft portion of the weight with the hole; and
weight holing portion moving means (device) for moving the weight holding portion up and down.
A spiral groove is formed on at least either the outer circumferential surface of the shaft portion of the weight or the inner circumferential surface of the hole of the weight holding portion.
In the second slider processing apparatus according to the invention, the weight holding portion can be moved up and down with the weight holding portion moving means (device) to select a state in which the lower end of the shaft portion of the weight does not contact with the slider holder and no load is therefore applied by the weight to the slider holder or a state in which the lower end of the shaft portion of the weight contacts the slider holder to apply a load originating from the weight to the slider. In this slider processing apparatus, chips (particles) generated by friction between the shaft portion of the weight and the hole of the weight holding portion are collected by the spiral groove formed on at least either the outer circumferential surface of the shaft portion of the weight or the inner circumferential surface of the hole of the weight holding portion to maintain a smooth operation of the shaft portion.
In the second slider processing apparatus according to the invention, for example, a plurality of the weight holding portions may be provided in the form of stages to hold a plurality of weights, and the load applying means (apparatus) may move the weight holding portions downward with the weight holding portion moving means (device) from a state in which the lower end of the weight held by the weight holding portion at the bottom stage is located above the slider holder without contacting the slider holder to load the slider holder with the weights held by the weight holding portions in the form of a plurality of stages sequentially from the bottom stage.
For example, the weights of the second slider processing apparatus according to the invention comprise one or more blocks having a predetermined weight.
Similarly to the first load applying apparatus, a second load applying apparatus for processing a slider is an apparatus for applying a load to a slider holder so as to urge a slider held by the slider holder against a lapping member, comprising:
a weight including a shaft portion which can be put into contact with the slider holder at the lower end thereof and a large diameter portion greater in the diameter than the shaft portion;
a weight holding portion formed with a hole which allows the shaft portion of the weight to pass therethrough and which disallows the large-diameter portion to pass therethrough, for holding the weight movably in the axial direction of the shaft portion of the weight with the hole; and
weight holing portion moving means (device) for moving the weight holding portion up and down.
A spiral groove is formed on at least either the outer circumferential surface of the shaft portion of the weight or the inner circumferential surface of the hole of the weight holding portion.
Like the second processing apparatus according to the invention, in this second load applying apparatus, chips (particles) generated by friction between the shaft portion of the weight and the hole of the weight holding portion are collected by the spiral groove formed on at least either the outer circumferential surface of the shaft portion of the weight or the inner circumferential surface of the hole of the weight holding portion to maintain a smooth operation of the shaft portion.
For example, the weight of the second load applying apparatus according to the invention comprises one or more blocks having a predetermined weight.
A third slider processing apparatus according to the invention is an apparatus for lapping edges of a slider having
a surface to face a medium to chamfer the edges, comprising:
a slider holder for holding a slider;
a lapping member having a lapping surface for lapping an edge of the slider held by the slider holder;
a positioning device for positioning the slider holder such that the slider contacts the lapping member with a surface of the slider to face a medium inclined relative to the lapping surface of the lapping member; and
moving means (device) for moving the slider held by the slider holder and the lapping member relative to each other such that the edge of the slider is lapped by the lapping member.
In the third processing apparatus according to the invention, the slider holder is positioned by the positioning device such that the slider contacts the lapping member with a surface of the slider to face a medium inclined relative to the lapping surface of the lapping member.
In the third processing apparatus, for example, the slider may include a plurality of edges having steps, and the lapping member may have flexibility. The processing apparatus may further have transforming means (device) for transforming the lapping member such that the plurality of edges having steps of the slider are simultaneously lapped by the lapping member.
A second method for processing a slider according to the invention is a method for lapping an edge of a slider having a surface to face a medium to chamfer the edge, including the steps of:
putting a slider in contact with a lapping member with a surface of the slider to face a medium inclined relative to a lapping surface of the lapping member for lapping an edge of the slider; and
moving the slider and the lapping member relative to each other in a state in which the slider is in contact with the lapping member with the surface of the slider to face a medium inclined relative to the lapping surface of the lapping member to lap a predetermined edge of the slider with the lapping member.
In the second processing method according to the invention, for example, the slider may include a plurality of edges having steps, and the lapping member may have flexibility. The lapping step may simultaneously lap a plurality of edges having steps of a slider by transforming the lapping member.
A third method for processing a slider according to the invention is a method for lapping an edge of a slider having a surface to face a medium to chamfer the edge, including:
a first lapping step for lapping a part of an edge of a slider in contact a the lapping member while moving the slider and the lapping member relative to each other in a state in which the slider is in contact with the lapping member with a surface of the slider to face a medium inclined relative to a lapping surface of the lapping member; and
a second lapping step for lapping a part of an edge of the slider in contact with the lapping member while moving the slider and the lapping member relative to each other in a state in which the slider is in contact with the lapping member with the surface of the slider to face a medium in parallel with the lapping surface of the lapping member.
In the third method for processing according to the invention, for example, the slider may include a plurality of edges having steps; the lapping member may have flexibility; and the first lapping step may simultaneously lap the plurality of edges having steps of the slider with the lapping member by transforming the lapping member. The second lapping step may lap the plurality of edges having steps of the slider with the lapping member by transforming the lapping member. For example, the slider may include a plurality of edges having steps, and the first lapping step may include the steps of lapping the edges of the slider with the lapping member without transforming the lapping member and simultaneously lapping the plurality of edges having steps of the slider with the lapping member by transforming the lapping member having flexibility. The first lapping step may chamfer at least a part of an edge in contact with the lapping member into a slanting surface, and the second lapping step may chamfer the edge chamfered into a slanting surface at the first lapping step into a curved surface.
A first auxiliary device for processing a slider according to the invention is a device for positioning a slider holder relative to a lapping member, which is used in a slider processing apparatus having a slider holder, lapping member and moving means, for lapping an edge of a slider to chamfer the edge.
The first auxiliary device according to the invention comprises:
a main body located above the lapping member; and
a positioning portion formed on the main body for positioning the slider holder such that a slider is put into contact with the lapping member with a surface of the slider to face a medium inclined relative to the lapping surface of the lapping member.
With the first auxiliary device according to the invention, the slider holder is positioned by the positioning portion such that a slider is put into contact with the lapping member with a surface of the slider to face a medium inclined relative to the lapping surface of the lapping member.
A fourth slider processing apparatus according to the invention is an apparatus for lapping edges of a slider including a plurality of edges having steps and a surface to face a medium to chamfer the edges, comprising:
a slider holder for holding a slider;
a flexible lapping member for lapping edges of the slider held by the slider holder;
a transforming device for transforming the lapping member such that the plurality of edges having steps of the slider are simultaneously lapped by the lapping member, having a main body located opposite to the slider held by the slider holder with the lapping member sandwiched therebetween and a wire wound around the outer circumference of the main body for transforming the lapping member; and
moving means (device) for moving the slider held by the slider holder and the lapping member relative to each other such that the edges of the slider is lapped by the lapping member.
In the fourth slider processing apparatus according to the invention, the lapping member is transformed by the wire of the transforming device, and a plurality of edges having steps of a slider are simultaneously lapped by the lapping member. The tension of the wire is stable because it is wound around the outer circumference of the main body.
The transforming device of the fourth slider processing apparatus according to the invention may further have an elastic member or projection provided under a part of the wire located on the upper surface of the transforming device.
A second auxiliary device for processing a slider according to the invention is used in a slider processing apparatus having the slider holder, lapping member and moving means like the fourth processing apparatus, for lapping edges of a slider to chamfer the edges and comprises:
a main body located in a position opposite to a slider held by the slider holder with the lapping member sandwiched therebetween; and
a wire wound around the outer circumference of the main body for transforming the lapping member such that a plurality of edges having steps of the slider are simultaneously lapped by the lapping member.
With the second auxiliary device according to the invention, the lapping member is transformed by the wire, and a plurality of edges having steps of a slider are simultaneously lapped by the transformed lapping member. The tension of the wire is stable because it is wound around the outer circumference of the main body.
The second auxiliary device according to the invention may further have an elastic member or projection provided under a part of the wire located on the upper surface of the auxiliary device for processing a slider.
Other objects, features and advantages of the invention will become clear enough from the following description.